Scientists at EPFL and the University of Geneva have developed a microfluidic device smaller than a domino that can simultaneously measure up to 768 biomolecular interactions. Understanding the specific details of how these interactions take place is thus crucial to our overall understanding of the fundamental mechanisms of living organisms. There are millions of possible combinations of molecules, however; determining all of them would be a Herculean task. Various tools have been developed to measure the degree of affinity between a strand of DNA and its transcription factor. They provide an indication of the strength of the affinity between them.